Gene Mutation Linked to Higher Risk of Colon Cancer Death
Increased risk depends on absence of mutations in another cancer-promoting gene
FRIDAY, Feb. 27 (HealthDay News) -- Mutations in a gene involved in promoting cell growth increase the risk of cancer-specific death in patients with colon cancer, and the increased risk appears to depend on the absence of mutations in another cancer-promoting gene, according to research published online Feb. 23 in the Journal of Clinical Oncology.
Shuji Ogino, M.D., Ph.D., from the Dana-Farber Cancer Institute in Boston, and colleagues examined the association between PIK3CA mutations and prognosis in 450 patients with curatively resected colon cancer.
The investigators found that 82 tumors (18 percent) had PIK3CA mutations. After adjusting for risk factors associated with cancer recurrence, patients with mutations had a higher risk of colon cancer-specific mortality (hazard ratio, 2.23). The effect of PIK3CA mutations on cancer survival appeared to depend on the absence of KRAS mutations. The presence of PIK3CA mutation was associated with a significant increase in colon-cancer-specific mortality among patients with KRAS wild-type tumors (hazard ratio, 3.80), but PIK3CA mutation did not have a significant effect on mortality among patients with KRAS-mutated tumors, the researchers report.
"Among patients who undergo a curative resection of colon cancer, PIK3CA mutation is associated with shorter cancer-specific survival," Ogino and colleagues conclude. "The adverse effect of PIK3CA mutation may be potentially limited to patients with KRAS wild-type tumors."